For the sake of convenience and safety, consumers often substitute artificial trees constructed of metal and plastic for natural evergreen trees when decorating homes, offices, and other spaces, especially during the holidays. Such artificial trees generally include multiple tree sections joined at the trunk and held erect by a floor-based tree stand. Traditionally, consumers wrap strings of lights about the artificial tree to enhance the decorative quality of the tree display. As more and more decorative light strings are draped around the tree, it becomes more and more difficult to provide power to the various light strings distributed throughout the tree.
To ease this burden to the consumer, manufacturers have created “pre-lit” or lighted artificial trees. Typical pre-lit trees include an artificial tree with multiple standard light strings distributed about the exterior of the tree. Wires of the light string are clipped to branch structures, while plug ends dangle throughout the branches. Generally, multi-purpose decorative light strings are used in pre-lit trees, often limited to 50 or 100 bulb assemblies, with a bladed power plug for insertion into the back outlet of another light string, or insertion into an alternating current (AC) power source.
As the popularity of such pre-lit trees has grown, so to have the bulk and complexity of pre-lit trees. Along with an increase in the number and density of branches of a typical pre-lit tree comes an increase in the number of lights and light strings on the pre-lit tree. This increased number of branches and lights can significantly increase the weight of the pre-lit tree making it difficult to lift and align individual trunk sections when assembling the tree. Further, the increased number of lights per tree, often as high as 1,000 or 1,500 lights, drastically increases the complexity of interconnecting and powering the numerous light strings.
It can be difficult to find and then properly connect the necessary plugs in order to power all of the light strings on the tree. Light strings may be connected to one another within a given tree section, or sometimes between sections, by connecting the strings end to end. Consumers need to be careful to follow the manufacturer's guidelines and not plug too many light strings together end-to-end and surpass the current-carrying capacity of the light string wiring. Due to such limitations, power plugs of the light strings may include receptacles for receiving other power plugs such that the power plugs may be “stacked” together, plugging one into the other. Short extension cords may be strung along the outside of the trunk to carry power to the various interconnected light strings. The result is a complex web of lighting that often requires a consumer to not only interconnect the plugs and receptacles of individual light strings together, but to stack and plug multiple light strings and cords into multiple power outlets.
Some known inventions have attempted to simplify the electrical connection of pre-lit trees by enclosing light wiring within the trunk of the tree and tree sections. For example, U.S. Pat. No. 1,656,148 to Harris filed Apr. 5, 1926 and entitled “Artificial Christmas Tree” teaches a simple artificial tree with one embodiment having multiple tree sections that join together. The tree includes single bulbs at each end of a branch, with bulb wiring extending from inside a trunk through hollow branches. A bayonet fitting is used to adjoin the sections, a top section having a projecting pin, and a bottom section having an L-shaped bayonet slot. The two sections are coupled by aligning the projection pin with the bayonet slot and rotating to interlock the sections, thereby bringing a pair of spring contacts into alignment with a pair of terminals to make an electrical connection.
Another known artificial tree as described in U.S. Pat. No. 3,970,834 to Smith, filed Dec. 16, 1974 and entitled “Artificial Tree”, describes a pre-lit tree made in sections which may be folded for easy storage. The individual tree sections include a threaded male end and a threaded female socket end. The male end of a tree section is aligned with, then screwed into, the female end of another section. Wiring for the lights passes from the trunk through holes in branches and connects with individual lights at an interior of the branch. When the tree is completely screwed together, an electrical connection is made.
Yet another known artificial, lighted tree as described in U.S. Pat. No. 8,053,042 to Loomis, filed Jul. 1, 2010 and entitled “Artificial Tree Apparatus”, describes a pre-lit tree having a first trunk segment with an electrical socket that couples together with a second trunk segment having an electrical plug. The tree segments also include a guide slot and detent structure on the trunk segments. To electrically and mechanically couple the first and second tree segments, the socket and plug must be aligned at the same time that the guide slot and detent are aligned.
A common feature of such known trees is that the first and second tree segments must be aligned in a particular position, or rotational orientation, in order to electrically and mechanically couple the two tree sections. However, the larger the size and heavier the tree, the more difficult it can be for a user to manipulate the two tree segments into alignment.
Conversely, some of the more traditional pre-lit trees with wiring outside the trunk may include tree sections that can be mechanically coupled in nearly any rotational alignment of the two trunk sections. However, depending on the coupling structure, the two tree sections may be able to rotate relative to another. Such rotation may be undesirable for both aesthetic and more practical reasons. For example, if a tree is in a corner, it may be decorated only on one side. Rotation of one of the tree sections relative to the other changes the decorative appearance of the tree. In another example, if one tree section is bumped or otherwise rotated relative to another, portions of the light string may become detached from the tree, or worse, wires may become detached from their lamp sockets or plugs.
While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.